var mongoose = require('mongoose'),    //加载mongoose模块
DB_URL = 'mongodb://localhost:27017/chileme';
mongoose.Promise = global.Promise;  
//连接数据库
mongoose.connect(DB_URL);
//连接成功
mongoose.connection.on('connected', function () {    
    console.log('Mongoose connection open to ' + DB_URL);  
});   
// 连接异常
mongoose.connection.on('error',function (err) {    
    console.log('Mongoose connection error: ' + err);  
});    
// 连接断开
mongoose.connection.on('disconnected', function () {    
    console.log('Mongoose connection disconnected');  
});   
module.exports = mongoose;   //导出mongoose对象
